On Thu, Jul 19, 2018 at 11:23:56PM +0530, Vivek Gautam wrote:
> Currently we check if the number of context banks is not equal to
> num_context_interrupts. However, there are booloaders such as, one
> on sdm845 that reserves few context banks and thus kernel views
> less than the total available context banks.
> So, although the hardware definition in device tree would mention
> the correct number of context interrupts, this number can be
> greater than the number of context banks visible to smmu in kernel.
> We should therefore error out only when the number of context banks
> is greater than the available number of context interrupts.
> 
> Signed-off-by: Vivek Gautam <[email protected]>
> Suggested-by: Tomasz Figa <[email protected]>
> Cc: Robin Murphy <[email protected]>
> Cc: Will Deacon <[email protected]>
> ---
>  drivers/iommu/arm-smmu.c | 19 +++++++++++++------
>  1 file changed, 13 insertions(+), 6 deletions(-)
> 
> diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
> index 7c69736a30f8..4cb53bf4f423 100644
> --- a/drivers/iommu/arm-smmu.c
> +++ b/drivers/iommu/arm-smmu.c
> @@ -2229,12 +2229,19 @@ static int arm_smmu_device_probe(struct 
> platform_device *pdev)
>       if (err)
>               return err;
>  
> -     if (smmu->version == ARM_SMMU_V2 &&
> -         smmu->num_context_banks != smmu->num_context_irqs) {
> -             dev_err(dev,
> -                     "found only %d context interrupt(s) but %d required\n",
> -                     smmu->num_context_irqs, smmu->num_context_banks);
> -             return -ENODEV;
> +     if (smmu->version == ARM_SMMU_V2) {
> +             if (smmu->num_context_banks > smmu->num_context_irqs) {
> +                     dev_err(dev,
> +                           "found only %d context irq(s) but %d required\n",
> +                           smmu->num_context_irqs, smmu->num_context_banks);
> +                     return -ENODEV;
> +             } else if (smmu->num_context_banks < smmu->num_context_irqs) {
> +                     /* loose extra context interrupts */
> +                     dev_notice(dev,
> +                           "found %d context irq(s) but only %d required\n",
> +                           smmu->num_context_irqs, smmu->num_context_banks);
> +                     smmu->num_context_irqs = smmu->num_context_banks;
> +             }

I don't see the utility in the new message. Can you simplify with the patch
below on top? It's a bit weird that we only decide to ignore the extra irqs
after calling platform_get_irq() on them, but that seems to be harmless.

Will

--->8

diff --git a/drivers/iommu/arm-smmu.c b/drivers/iommu/arm-smmu.c
index aa46c1ed5bf9..5349e22b5c78 100644
--- a/drivers/iommu/arm-smmu.c
+++ b/drivers/iommu/arm-smmu.c
@@ -2109,13 +2109,10 @@ static int arm_smmu_device_probe(struct platform_device 
*pdev)
                              "found only %d context irq(s) but %d required\n",
                              smmu->num_context_irqs, smmu->num_context_banks);
                        return -ENODEV;
-               } else if (smmu->num_context_banks < smmu->num_context_irqs) {
-                       /* loose extra context interrupts */
-                       dev_notice(dev,
-                             "found %d context irq(s) but only %d required\n",
-                             smmu->num_context_irqs, smmu->num_context_banks);
-                       smmu->num_context_irqs = smmu->num_context_banks;
                }
+
+               /* Ignore superfluous interrupts */
+               smmu->num_context_irqs = smmu->num_context_banks;
        }
 
        for (i = 0; i < smmu->num_global_irqs; ++i) {
_______________________________________________
iommu mailing list
[email protected]
https://lists.linuxfoundation.org/mailman/listinfo/iommu

Reply via email to